Sunny Boy in the Island Grid System
SMA
Solar Technology AG
156
SI2012_2224-TEN082311
Technical Description
15.2 Frequency Shift Power Control (FSPC)
This section describes how the power adjustment via frequency "Frequency Shift Power Control
(FSPC)" functions.
If Sunny Boy inverters are connected to the AC output side of a stand-alone grid, the Sunny Island
must be able to limit their output power. This situation can come about when, for example, the Sunny
Island's batteries are fully charged and the (solar) power available from the PV generator exceeds
the power required by the connected loads.
Using a Communication Bus
If the Sunny Boy and Sunny Island are operated together on one communication bus, the
"250.06 ComBaud" parameter in the Sunny Island must be set to "1200" (default).
The Sunny Island only communicates through the SMA-Net protocol, Sunny-Net is not
supported.
Settings in Older SMA Inverters
It may happen that older SMA inverters cannot yet be set to "Offgrid" (stand-alone grid)
via the "Default" parameter. In this case, the values 1 - 6 in the table must be set
individually.
FSPC
The frequency-based power control works only in stand-alone mode!
Inverters without FSPC
This function is neither supported by the SMA PV inverters SB2100TL, SB3300TL,
SB4200TL and SB5000TL, nor by older models in the SWR series. But these Sunny Boys
can nevertheless be used in island grid systems.
If the present battery voltage is higher than the nominal battery voltage (VBatt nom), the
Sunny Boy inverters mentioned above are disconnected from the stand-alone grid present
at that time, and are only reconnected after a battery discharge of at least 5 %.
